1. Field of the Invention
The present invention relates to a washing machine, and more particularly to a washing machine and steam washing method thereof that washes laundry with steam generated by heating wash water with a wash heater.
2. Description of the Related Art
Generally, a washing machine includes a cabinet, a tub adapted to contain wash water, a drum disposed inside the tub, a drive motor adapted to drive the drum, a water supply valve connected to the tub to supply wash water to the tub, and a detergent container connected to the water supply valve and containing detergent. Additionally, the washing machine includes a drain unit extending from the tub to the outside of the cabinet, a steam generator disposed between the water supply valve and the detergent container, and a steam heater provided to the steam generator to generate steam by heating wash water.
The washing machine performs steam washing as follows.
First, water is supplied into the steam generator and heated by the steam heater provided to the steam generator to supply steam into the drum where laundry has been received. While steam is generated by the steam heater, the drive motor rotates the drum in the forward and reverse directions to agitate the laundry inside the drum for steam washing. During the steam washing, the steam generated by means of the steam heater sterilizes bacteria and fungi in the laundry. During a washing cycle after completion of the steam washing operation, a wash heater can be operated to heat wash water inside the tub or the steam heater can be operated to supply steam into the tub.
However, the washing method of the conventional washing machine entails substantial power consumption since the steam heater is continuously operated from start to end of the washing operation to supply steam to the laundry. Moreover, in the conventional washing machine, since washing and rinsing cycles are carried out after the steam washing, bacteria or fungi can be attached to the laundry during the washing and rinsing cycles, thereby deteriorating sterilizing effects of the steam washing.